Hello there, @userSDnVVa6ZtT. I'm glad you reached out here with your concern.
I certainly want to assist you further with this matter. To better do that, can the Community have the exact model number and Baseband version (both under Settings>About Device) for your device as well as your carrier and what you've already tried to fix it? Thanks!
Thank you for that information. Just to be sure I don't repeat things you might have already tried, have you done any troubleshooting to fix this already?
Hi, I don't know if you already figured out your problem, but I was having the same problem when I updated to Oreo. I have the Google messenges as my main texting app, but when I got the Oreo update, the setting for notifications from the Samsung messages app was turned on and I was receiving sound notifications without a badge or notification in panel. I turned off notifications for the Samsung messages and then went through my app list and made sure the apps I didn't want notifications for weren't switched to on after update. Some apps we're switched on, so I turned the notifications off for those again, and haven't had any problems since....so I guess it could've been ghost notifications from a different app, but it's fixed for me now.